Diazoamino compounds



United States Patent (3 DIAZOAMINO COMPOUNDS Eduard Moser, Basel, Albert Bolleter, Muttenz, and Christian Wittwer, Basel, Switzerland, assignors to Ciba Limited, Basel, Switzerland, 21 Swiss firm No Drawing. Application August 20, 1954,

Serial No. 451,295

This invention provides valuable new diazoamino compounds which, like the compound of the constitution OH; HO O C correspond to the general formula HO O O X 1|1-N=N-N S 03H it i in which R represents a benzene radical, X and H are each in ortho-position relatively to the N=N group, X represents a methyl, methoxy or ethoxy group (U) or a hydrogen or chlorine atom, and Z represents a methyl or benzyl group (V) or a straight chain alkyl radical (W) containing 2 to 4 carbon atoms and bound to the nitrogen atom by an end carbon atom, and in which formula the radical is the radical of an amine of the constitution which is free from groups imparting solubility in water and of which the pKA-value differs by at most from the value 4: where the latter value is oneof the following The invention also provides a process for making the above new diazoamino-compounds wherein a l-aminobenzene-Z-carboxylic acid-4-sulfonic acid of the formula 2 in which Z has the meaning given above, is condensed with a diazo-compound of an amine free from groups imparting solubility in water and having the formula in which R and X have the meanings given above, and X and H are each in ortho-position relatively to the NH: group, and wherein the starting materials are so chosen that the pKn-value of the latter amine and the value c fulfil the above requirements.

The 1aminobenzene-2-carboxylic acid-4-sulfonic acids of the Formula 3 contain a secondary amino group, of which the nitrogen atom is bound either to a methyl or benzyl group (Z=V) or to an end carbon atom of a straight chain, that is to say, unbranched, alkyl group having 24 carbon atoms (Z W). In the latter case Z is therefore an ethyl, n-propyl or n-butyl group. As examples of such compounds there may be mentioned:

(Z=V): l methylaminobenzene 2 carboxylic acid 4-sulfonic acid, 1- benzylaminobenzene 2 carboxylic acid 4-su1fonic acid, (Z=W): l-ethylaminobenzene 2 carboxylic acid 4-sulfonic acid, 1 n butylaminobenzene 2 carboxylic acid 4-sulfonic acid.

The amines of the Formula 4, of which diazocompounds are used as starting materials in the present process, are amines of the benzene series. They contain no substituents in one of the ortho-positions relatively to the diazotizable amino group and in the other of these ortho positions they may be unsubstituted or contain a chlorine atom or a methyl, methoxy or ethoxy group. The benzene nucleus may contain further substituents which do not impart solubility in water and are present in positions other than an ortho-position relatively to the amino group, for example, halogen atoms such as chlorine, or methyl, ethyl, methoxy or ethoxy groups, trifluoromethyl groups or ni-tro groups. Thus, the amines may be unsubstituted in para-position relatively to the amino group or may contain in that position a chlorine atom, a methyl, methoxy or acylamino group. There come into consideration, for example, the following amines:

l-amino-3-chlorobenzene, 1-amino-Z-methyl-4-chlorobenzene, 1amino-Z-methyl-S-chlorobenzene, 1-amino-4-methylbenzene, 1-amino-4-methoxybenzene, 1amino-Z-methoxy-Schlorobenzene, 1amino-Lmethoxyl-chloro-S-methylbenzeue, 1amino-2-methoxy-4-benzoylamino-S-methylbenzene, l-amino-Z S-dimethoxy-4-benzoylaminobenzene, l-amino-Z 5 -dieth0xy-4-b enzoylaminobenzene, l-amino 2-chloro-4-methoxybenzene.

The 1aminobenzene-Z-carboxylic acid-4-sulfonic acids of the Formula 3 and the diazo compounds of the amines of the Formula 4 cannot be chosen at random for combination with one another, but the amine must be so chosen that its pKA-value is not more than 0.7 higher or lower than the value C f The value c depends on the nature of the substituent in ortho-posi-tion relatively to the amino group of the amine (X=H,Cl,CHa,OCHa or OC2H5) and on the nature of the substi-tuent in the amino group of the aminobenzene carboxylic acid sulfonic acid (Z=V or W).

In order to determine whether 'a particular combination of starting materials falls within the invention, the pKA-value of the selected amine must be known, and then it can easily be determined whether this value differs by at most $0.7 from the value c given above for the particular substituents X and Z of the chosen combination. .Thus, for example, the pKA-value of 1-amino-4- methoxybenzene is 5.3, in which case X is a hydrogen atom. If this amine iscombined with l-methylaminoor 1-benzylaminobenzene-Z-carboxylic acid-4-sulfonic acid (Z=V), the value c =c flv, =4.8. The latter value differs from 5.3 by less than 0.7, so that this coma bination falls within the invention. If, on the other hand,

o p the same amine is combined with l-ethylaminobenzene-2 carboxylicacid-4-sulfonic acid (Z=W) the'va'lu'e (x;z)= (x=H;z=W which differs from 5.3 by more than. 0.7, so that this combination or the, compound obtainable thereby does not fall within the invention. I According to recent textbooks the pKA-value of th amine RNH'2'is derived from the equilibrium 1a1 i1r.:1t NH.+H

of which the acidity constant is z),-(H ee) the symbols for the components of'the equilibrium enclosed within curved brackets representing the activities of'these components.

The pKA-value is defined. by the relationship 7 v i in p A= s A.

Fuller information with; regard to the pKn-valueand its determination, which may be. carried out. by an. acidimetri c,.conductometric or colorimetric. method, may be obtained, for example, from Physical Chemistryof-Electrolytic Solutions by H. S. Harned and BB. Owen, Chapter 15/4, 1943 edition, pages 480 et seq.

In order to facilitate determination ofthefpermissible deviations of' the pKA-values from the. basic values. for c k the following table'may. be, used. From thistable direct readingsc'ani be obtained: of the limits within which the pKarval'ue of a particular base may vary for given 'substituents X in ortho-position to the amino group of the. amine and for given nitrogen-substituents Z in the 1 aminobenzen-Z-carboxylic acid-4-sulfonic acid.

PERMISSIBLE PKA-RANGE OF THE AMINE The preparation of the diam-compounds of the-amines of the Formula 4. and. the reaction of these amines with the 1-'aminobenzeneQ-carboxylicv acidr4-sulfonic acids. of the Formula 3..m-ay be carriedout'by methods in them.- selves known. The condensation to formthediazoaminov compounds is advantageously carried out in. an alkaline medium. It has been found that the diazoamino-compounds: soobtaine d cannotbe isolated. satisfactorily. from thereaction mixture'by the-usual methods. It; is: surpriseing,-,however, that these reactionmixtures; can be worked up very. successfully,--i f= desired after filtering.them to re move, undissolved impurities, by subjecting; the; resulting solutions of the diazoamino-compounds to a rapidrdrying process Asza rapid; drying-process there is tobeunderstood one in which thematerial tobe dried is'subjected: to: a high-temperature in the; aqueous condition only. for aashorttime,advantageously a periodof the order. of. a few seconds, but it is permissible once the; material. is dried, to maintain it at a high temperature.- for. a long PfiIlOCl-f Accordingly-there are suitable; dryingori evaporation methods in which the solution to be. evaporated to.= dryness isgcontinuously exposed-in a. finelydivided; state. to a powerful. source of" heat; and advantageously care. is. taken. that: the-Water vapourv evolved is1continuously-an'd :efiiciently removed.

'7 Especially advantageous for thispurposeis spray drymg. The termfsp ray drying" is used in'its ordinary sense to. mean a treatmentin which the-aqueous solution or suspension-to. be dried is finely sprayed or'atomized and. simultaneously exposed to -a.- currentof Warm; air. The heatof the. current of; air is used to evaporate-tho solvent, especially water. In this mannerthe air-solvent vapdiir 'dfy 'inaterial"system undergoes cooling. For drying aqueous solutions or suspensions to produce a dry preparation it is generally necessary to maintain the outlet temperature of the said system at at least about C., advantageously between and C., and for the same reason itlis necessary that the inlet. temperature of the air should be. above 100C advantageously within the range of l3 0 -18 O C. in, orderto avoidjh'aving to heat uneconomically. large amounts of Instead of spray drying, there may be used another rapid drying process, 'forexample, adrying process in which the cold solution or suspension is applied in a thin layer to, a hot roller or moving-band, Iii-this casealso it"is preferable, on the one ha ndby heating to a sufiiciently high temperature the moving surface, for example, the roller, and, on the other, by finely distributing the material to be dried, for example, by breaking'it up into dropletsv or by spraying. it, to ensure. that'a thin uniform film of the material to be dried is formed from which the solvent can be completely distilled in a short time. After a short time the dry layer is completely removed from the hot surface by means of a knife or other suitable apparatus, the material being removed in any event before fresh solution is applied'to the place it occupies.

It is surprising that during such rapid drying processes there is at most only avery slight decomposition of the diazo-compound. or diazoamino-compound, and even in cases Where, owing to anun'favorable equilibrium between the starting materials and the diazoamino-compound being established when the condensation was carried out, a not inconsiderable amount of the temperature-sensitive diazo compound-is still present.

The new diazoarnino-compounds of the Formula 2 can be worked up inthe usual manner together with suitable coupling components (so-cal=led naphthols"), for example, acetoacetylamino-compounds, 2-hydroxynaphthalene-3- carboxylic acid arylides, hydroxydiphcnylene oxide carboxylic acid arylides, hydroxycarbazole carboxylic acid arylides or hydroxyanthracene carboxylic acid arylides, to form valuable preparations and printing pastes, which do not require acid steaming for developing the prints and therefore needno addition serving to'produce an acid reaction. It will be understood, however, that development may be carried out by acid steaming, in which case only a very short period of acid steaming is usually necessary for complete development.

The, following examples illustrate the invention, the parts and percentages being by. weight unless o herwise stated,yandthe ,relationship of parts by. weight; to parts. by volume being the same as that of the kilogramto the liter:

Example I 17.8; parts of. the hydrochloride of l-amino-Z-methyl- 4rchlorobenzene (pKA,=3.8) are diazotizedinvthe usual manner-at 07 C.,in: 45 parts of hydrochloric acid of 1 0 -percent=strength with 6*.9-parts of sodium nitrate. dissolved in 25 parts of water. The volume of the diazo solution should be 200 parts by volume. At the same time there is prepared'a solution of 23.1 parts of 1-methylaminobenzene 2 carboxylic acid-4-sulfonic acid in 200 parts of water with the addition of a sufficient quantity of a sodium hydroxide solution. of- 30percent strength to maintain theclear solutionat a pH- .value' of 7-8. There. arethen addedi2i parts of anhydrous sodium carbonate and 2 parts of sodium bicarbonate, and the whole is cooled to 4' C. in an ice-sodium chloride bath, and, if necessary, by the addition of ice. The diazo solution is run in below the surface while stirring vigorously, and at the same time. a suflicient quantity. of a sodium hydroxidefisolution. of. 30 percent strength is introduceddropwise to maintain the mixture at a pH valueof 19.5.v to l0 and togive a final.pH ;va-lue of 10, After the addition: of-diat'omaceous. earth; the mixtureis filtered to remove a small amount of fiocculent material, and the solution is then sprayed in a spray dryer, in

which the inlet temperature of the air is between 130 and Example 2 10.7 parts of l-amino-4-methylbenzene (pK .=5.0) are diazotized in the usual manner in 75 parts of hydrochloric acid of 10 percent strength with 6.9 parts of sodium nitrite dissolved in 25 parts of water. At the same time there is prepared a solution of 23.1 parts of 1-methylaminobenzene-Z-carboxylic acid-4-sulfonic acid in the manner described in Example 1. The diazo solution is run in beneath the surface at to 4 C., and at the same time a sufiicient quantity of a sodium hydroxide solution of 30 percent strength is added to maintain the mixture at a pH value of 9.5 to 10. Finally the pH value is adjusted to 10 with a solution of sodium hydroxide, and the mixture is filtered with the aid of diatornaceous earth to remove a small amount of impurities. The clear solution is worked up in a spray dryer as described in Example 1. There is obtained a pale powder having a content of about 45 percent of the diazoamino-compound and in a yield of approximately 80 percent of the theoretical yield.

By using, instead of 10.7 parts of 1-amino-4-methylbenzene, 12.3 parts of 1-amino-4-methoxybenzene (PKA=5.3) and otherwise proceeding in the same manner, the corresponding diazoamino-compound is obtained in the form of a pale brown powder having .a content of about 45 percent and in the same yield.

Example 3 17.1 parts of 1-amino-Z-methoxy-4-chloro-S-rnethylbenzene (pKA=4.1) are diazotized as described in Example 1 and filtered. The volume of the diazo-solution should be 150-200 parts by volume. At the same time there is prepared a solution of 23.1 parts of l-methylaminobenzene-2-carboxylic acid-4-sulfonic acid in 200 parts of water with a sufiicient quantity of a sodium hydroxide solution of 30 percent strength to give the clear solution a pH value of 7-8. There are then added 2 parts of anhydrous sodium carbonate and 2 parts of sodium bicarbonate, and the mixture is cooled to -3 C. The diazo-solution is then run in beneath the surface and at the same time a sufficient quantity of a sodium hydroxide solution of 30 percent strength is added to maintain the pH value between 9.5 and 10. When the mixing operation is finished, the pH value is adjusted to 10 with a sodium hydroxide solution of 30 percent strength, a small amount of diatomaceous earth is added, and the mixture is filtered to remove a small amount of impurities. The diazominocompound is isolated in a spray dryer as described in Example 1. There is obtained a pale beige powder having a content of diazoamino-compound of about 50 percent and in a yield amounting to about 85 percent of the theoretical yield.

Example 4 v 25.6 parts of 1-amino-2 methoxy-4 benzoylamino-5- methylbenzene are stirred overnight at room temperature in 100 parts by volume of water with 30 parts of hydrochloric acid of 30 percent strength and 2 parts of a solution of 30 percent strength of the hydrochloride of oleyl-diethyl-ethylenediamine, the mixture is then cooled to 0-5 C. and diazotized with 6.9 parts of sodium nitrite in 25 parts of water. The filtered diazo-solution is coupled in the manner described in Example 1 with a solution, also prepared as described in that example, of 23.1 parts of 1-metbylamino-benzn-Z-carboxylic acid- 4-sulfonic acid, the pH value of the reaction mixture being maintained between 8 and 9, and finally adjusted to 9. After filtering the mixture in the presence of diatomaceous earth, the product is worked up in a spray dryer. form of a pale brown powder which dissolves easily in water and has a content of 50 percent. The yield amount to about 75 percent of the theoretical yield.

Instead of 1-amino-2-methoxy-4-benzoylamino-S-methylbenzene, there may be used 27.2 parts of 1-amino-4- benzoylamino-2:S-dimethoxybenzene or 30.0 parts of 1- amino 4 benzoylamino 2:5 diethoxybenzene. The pH value of the reaction mixture is then maintained between 9 and 11 by the addition of a somewhat larger quantity of a sodium hydroxide solution of 30 percent strength, and thepH value is finally adjusted to 11. By evaporating the solution in a spray dryer the corresponding diazoamino-compound is obtained in the form of a pale brown easily soluble powder having a content of 50-60 percent and in a yield of 75-80 percent of the theoretical yield.

pKA-values of the bases 1 amino 2 methoxy 4 benzoylamino 5 methylbenzene 4.5 1 amino 4 benzoylamino 2:5 dimethoxybenzene 4.0 1 amino 4 benzoylamino 2:5 diethoxybenzene 3.9

Example 5 whole is then mixed with the diazo solution as described.

in Example 1, and the solution is worked up in a spray dryer. There is obtained a pale powder which dissolves easily in water and has a content of about 50 percent of the diazoamino-compound. The yield amounts to -85 percent of the theoretical yield.

By using, instead of 1-ethylaminobenzene-Z-carboxylic acid-4-sulfonic acid, 27.3 parts of l-n-butylaminobenzene-2-carboxylic acid-4-sulfonic acid and proceeding otherwise in exactly the same manner, there is obtained in the same yield a powder having similar properties.

Example 6 19.4 parts of the hydrochloride of 1-amino-2-methoxy-.

S-chlorobenzene (pKA=3.5) are diazotized as described in Example 1. The volume ofthe filtered diazo-solution should be -200 parts by'volume, At the same time there is prepared a solution of 24.5 parts of l-ethylaminobenzene2-carboxylic acid-4-sulfonic acid in 300 parts of water with a sufiicient quantity of a sodium hydroxide .solution of 30 percent strength to give a clear solution having a pH value between 7 and 8. 2 parts of anhydrous sodium carbonate and 2 parts of sodium hydrogen carbonate are added, and the mixture is cooled to 3 C. The diazo-solution is run in beneath the surface, while stirring well, and at the same time there is added a sufficient quantity of a sodium hydroxide solution of 30 percent strength to maintain the pH value of the reaction mixture between 10 and 11. The whole is stirred for a further /2 hour at 0-5 C., and is then filtered with the addition ofdiatomaceous earth to remove a small amount of a flocculent precipitate. The clear brown solution is evaporated in a spray dryer as described in Example 1. The diazoamino-compound is obtained in The diazoamino-compound is obtained in the.

theform of its sodium salt as a brown powder easily solublein-water.

13 By using, instead of 1-ethylan1inobenzene-2*carboxylic acid-l-sulfonic acid; 30.7 parts of 1-'benzylarni'nobenzeneparts of=the hydrochloride of1-amino-2-methyl-4-chloroeenze eand 23 .1 parts of-1-methylaminobenzene-Z-carboxylie acid-4-sulfoni cfacid. After being filtered the solution is charged into an externally cooled pressure 2-carboxylic acid-4-sulfonic acid and otherwise procee'cl- 5 vesselaridrnaintained therein at a temperature of-2-to ing inexactly the same manner, the corresponding di- 0 In order to isolate the diazoamino-compound;the azoamino-compound is obtained in a yield of 80-85 perfollowing apparatus is used: centin the form of a pale beige powder of good solu- An externally chromium plated and polished hollow bility andhaying a content of 55- percen t." T steel roller is horizontally mounted for (free rotation. It Exam f 10 has a connection for superheated steam at a maximum of V 6 atmospheres gaugepressure. A brass knifeis pressed In thesmanner described in Example 6 there is pr against the roller by means of weights at approximately p i mp u rom ed thelevelof its axis. At 21, distance of 20-25-centimeters amino 2 methyl 5 chlorobenzene (1516x 34); and from the roller, surface there is arranged perpendicularly :e y Q YHQ-acid-4 11 011 9: cl fl 15 with respect to the centre of the axis a nozzle connected to Byiusing; instead of 1 ethylammobenZene-Z-carb0Xyl1c the pressure vessel, the nozzle being so adjusted that the. aci'de4 sulfonic acide 27.3: parts or. l-n-butylam inobensupply ofthe solutionunder 2-5 atmospheres gg uge pr e zene- 2.-carboxyl ic acid-4-sultonic QCld-fllld OlhtBlWlSB prosure sutfices, without the special air supply, to atomise ceeding inexactly the same manner, the new diazoammo the solution finely and spray it on the roller. With a compound is obtained in the form of a palebrownpowder roller.20 centimeters in radiusand 20-25 centimeters long having acontent of 55-60 percent and an exeellent soluand; :ata speed of rotation 01f about 6 revolutions per billty. The yield amounts to about 85 percent of the minute, the nozzleand knife are so adjusted that the two theoretical yield. planes which they form with the roller axis are at an 7 Example 8 an-gleor 120. The residence. time on the roller of the 19.4 parts of the hydrochloride of 1-amino-2-chloro-4- {mate-rial to be dried is then p the roller rotatmethoxybenzene (PKA=3.5) are-diazotized-inthe usual from, the nozzle to f kmfe my thc'dlrecnon of the manner in 45 parts ofhydrochloric acid of l0percent P betwlaen The-quanmy Ofthg solu' strength with 6.9 parts of sodiumnitrite dissolved in non sprayed 1873-4 hairs-per. and the Surface: 25 parts of Water at Atthe same time there is perature .of the roller is 115-140 C. (corresponding to prepared as described in Example 5 a solution of 24.5 Q Q-Q gauge-pressure of a P I, Qf.-,1-ethylarninobenzenefi-carboxylic.acid-4-sulfonic sdla-zvovammo'compound 1S removed-fromaQid and the solution is coupledwithjhe dia-zo-solution, t r01 53' m a 5 brown F Elm-{must ate-3.." C, the pH value beingmaintained at.9.5-l0 by be p -i Short m-order attain-a uniform? addifibn of a sodium hydrdxidesolufion of 30 p line grain size. The.product so obtalned does not differ a g' and at the end of. the coupling theapflk mats content, yield or propert1es from the product obadjusted to 11. The product is worked up, as tamed by drymg m Example. describedin the preceding, examples, in a Spray dryer, The solutionsobtalned as described in Examples 2-8 after thQSOlllliQn has been filtered with the aid of asmall can wolked m the Same manger Therellre 'theni amount def: diatomaceous. earth. The diazoamino-comobtameddmzoammo'compounds Whlch do not'dlfier li'suia vedry Slightly yellow r powder having a 4.0 stantailly from the products obtained by spray dry-mg. content. of about 50 percent. The yield amounts to Exam 1 10 75-80 percent of the theoretical yield. p

- E xample 9' The diazoamino-compounds described in Examples1-9.

I 5 can be worked up into printing preparations in accord- Inthe. manner described 111 Example 1 there is pre; ance with the following table: pared a solution of the drazoamino-compound from 17.8 For 100 parts ofprinting preparation 7 V Diazoahiinogeompoundtrom V w I Sodium Accorddi-iso Parts 7 C t t Elngtol Parts... Coupling component propgl Tint on en Diem-component Stabilizer percent xamp 32m sulfonate A 712 i1 a;am.; '2.sa1j.yi;4. l-methyl-aininoz-i so 1 V 22.8 213- h tr '7 hth 1 1 i1 ehlorobenzene. glalll'gofizlearilgene-4f zfiidlfiii e thglanflizl 1 0 Bus red V V V I V a-sa B' 69.1 l-amino--methyldo 2 29.9 .S-hydro-oxycarbazole- 1.0 Red brown.

- benzene.- lcarlilojfiyllc acid -4 v ora 'e. O; 74. 6 1on1i110-2-rnethoxy-4- .,do 3 24.5 l-acetoacetylamino-ZE 1.0 Yellow.

' g gg et y gimethoxy -4 -chloro- 91129118. D. 76:8 I-amlnd-t-benzoyld 5 h 7 1 :gyggggfififdiethoxy V 0 a 4 22 2 2201C? 10 Blue E 72 .5 'l-amiiio- -benzoyldo B0. 4. 2 ..5 -h d l ii ttfzisi 6 tll 'ii if 1 0 'R'edmshvm 7 811 8. 3-58. F 73.? 1-bamlno- $='chlo1jol-ethylamino z-oar- 45 5 25.7 2:3 hydroxyn'aphthole 1.0 Yellow orange.

- V nzene. pooitiylggilgene -4-sul- TGHd-ZI; -methylenll1de G..... 68.1 l' arnino-z-methyl- .do 7 30.9 2:3 hydroxynaphtho1e 1.0 Scarlet.

- .r-chlorobenzene. fieild I-q2 elthoxy ani- H 77.2 l-amino-Q-methdxy: l benzylamino-2-car- 45 6 21.8 l-ac tyl ir ilno-2-meth- 1.0 Yellow.

' chlorobenzene. gtgiiggililfiile -4 suloxyg tilalcetoacetylarnl I 70. 8 l-amino-2- ohloro-4- lethylaruiliobenzenm 50 8 28.2, asii fl ai o i fiii bm 1.0 Red.

methoxybenzene. 2-carboxylicacld-4- acid-2 -ethoxyanll1de sulfomc acld. Na-salt.

9 With thesepreparations printing pastes maybe .prepared as follows: I

a methyl group, a methoxygroup andabenzoylamino group, X and H are each in ortho-position relatively to A B O D E F G H I Printing preparation 80 80 70 50 50 80 60 60 Urea 50 30 Glycerine 30 30 Alcohol 3O 30 30 I30 Thiodiethylene glycol 30 50 50 50 30 30 50 30 sotdium diisopropyl-naphthalene sulfonate, solu- 20 on..- Water. 260 320 355 310 285 310 280 310 250 Sodium hydroxide solution of 30 percent strength. 20 20 15 10 10 ll) 10 Starch-tragaeanth thickening 600 500 500 600 550 550 550 500 550 Sodium chlorate 10 10 10 10 10 10 10 10 10 Terpentine oil 10 10 10 10 10 10 10 10 10 1, 000 1, 000 1,000 1,000 1, 000 1,000 1, 000 1} 000 1, 000

A cotton fabric is printed With these printing pastes. The printed material is dried at 50-60 C., and then steamed under neutral conditions in a Mather-Flatt apparatus for 5-8 minutes at 100 C. The material is rinsed in the cold and treated with an enzyme preparation for 10 minutes at 40-50 C. in order to remove the starch. It is then rinsed in the cold, soaped at the boil for 10 minutes and dried after being again rinsed. There are obtained pure strong prints. The same strong prints are also obtained by steaming under acid conditions for 2-3 minutes at 100 C. instead of underneutral conditions.

What is claimed. is:

l. A diazoamino compound of the formula HO O C If I in which R represents a benzene radical, X and H are each in ortho-position relatively to the -N=N-- group, X represents a member selected from the group consisting of a hydrogen atom, a chlorine atom, a methyl group, a methoxy group and an ethoxy group, the latter three substituents being denoted by the symbol U, Z represents a member selected from the group consisting of a methyl group, a benzyl group and a straight chain alkyl radical containing 2 to 4 carbon atoms and bound to the nitrogen atom by an end carbon atom, the methyl and benzyl group being denoted by the symbol V and the alkyl radical containing 2 to 4 carbon atoms by the symbol W, and in which formula the radical which is free from groups imparting solubility in water and of which the pKa-value diifers by at most 10.7 from the value 0 where the latter value is determined in accordance with the substituents present in the diazoamino compound and with the equations in which R represents a benzene radical carrying in paraposition to the -N=N' group a member selected from the group consisting of a hydrogen atom, a chlorine atom,

the -N=N- group, X represents a member selected from the group consisting of a hydrogen atom, a chlorine atom, a methyl group, a methoxy group and an ethoxy group, the latter three substituents being denoted by the symbol U, Z represents a member selected from the group consisting of a methyl group a benzyl group and a straight chain alkyl radical containing 2 to 4 carbon atoms and bound to the nitrogen atom by an end carbon atom, the methyl and benzyl group being denoted by the symbol V and the alkyl radical containing 2 to 4 carbon atoms by the symbol W, and in which formula the radical R-N=N- is the radical of an amine of the constitution which is free from groups imparting solubility in water and of which the pKA-value differs by at most :0.7 from the value 0 (X3) Where the latter value is determined in accordance with the substituents present in the diazoamino compound and with the equations in which R represents a benzene radical, mand n each SOsH which is free fromgroups imparting solubility;i vtgaterv a nd of which the pKA-yaIue dit'fets byat most :0.7 from 3.5.

is the radical of an amine of the constitution Omn-tCnHInH 10 R-ENH:

Th diazqam no .eqmp u d f th form a.

C Ha a '7. The. diazoaxninotcompound of theformula 7 7 H300 8. The diazoamino compound of the formula OCH; Hoot N=NIII 8on1 CzH5 1 9,. The diazoamino compound of the formula CH3 H000 Y.VN=N.IIQ' span H a G1 5 References Cited in the file of this patent UNITED STATES PATENTS 2,622,838 Petitcolas et a1. Sept. 19, 1950 2,675,374 Petitcolas et a1. V Apr. 13, 1954 F REIGN PATENT 1,049,221 France Aug. 12, 1953 

1. A DIAZOAMINO COMPOUND OF THE FORMULA 